The present invention relates to a print head for matrix printers using wires or needles as styli, the styli being electromagnetically actuated and, more particularly, the present invention relates to a construction for such a head which includes a carrier for the several coils as well as for a corresponding plurality of magnetic yokes and armatures, the armatures having pivot arm function and abut the rear end of the needles or wires; the front end of these styli impact upon a record medium such as paper or the like upon respective energization and/or deenergization of the electromagnetic coils.
Print heads of the type to which the invention pertains reciprocate usually in front of a parallely arranged platen and the record medium is interposed between the platen and the print head. Continuous or step-wise advance of the record medium in conjunction with the operation of the print head produce alpha-numerical characters. The overall operation has as one of its parameters the reciprocating speed of the head; another parameter is the frequency of operation of the individual styli. These parameters are, of course, decisive of the overall print speed but also for the precision and accuracy of printing the appearance of the sign and, finally, on the life of the head.
Print heads are known in a variety of constructions characterised by various degrees of complexities which reflect on one hand in numerous tolerances which occasionally may occur cumulatively resulting in overall inaccuracies of the manufacturing and these inaccuracies are, for example, reflected in positional errors for the styli, the armatures and other movable parts. Therefore, the known print heads operate comparatively inaccurately and wear rather rapidly so that their life is quite limited.